Abstract: For promoting management of Inner Mongolia steppe,we evaluated the processes of grassland biomass formation and suitable grazing parameters.The results show that forage biomass is a single peak curve while the diurnal forage yield is a double peak curve during the period of spring to autumn.Based on the forage yield dynamics and phenology,we recommend the grazing date starts from the last ten-day of May,and ends in the last ten-day period of September or the first ten-day of October for a period of 120 d~140 d.The optimal stocking rate is 8 Au·hm^-2~9 Au·hm^-2 (sheep) for the grazing season.The growth potential of grazing lambs could attain 160 kg·hm^-2~180 kg·hm^-2,and at least a 23% increase in grass yield,and thus has very good economic benefits.